Without fail the class would end a few minutes early. As soon as I started making the sounds it was like dominoes. Ten minutes left in the lecture but everyone has all their stuff put away and are putting their coats on. I think of this often. May this knowledge set you free a few minutes early.
For me another part is the total lack of empathy these people have for the lecturer and those who are listening. Like come on you are sitting shoulder to shoulder to someone who is trying to listen to someone much further away than you are. Like I would imagine engineering students would have an understanding of the square cube law but I guess not. On top of that this is a room literally designed to amplify the sounds made inside of it.
AND ON TOP OF THAT apparently they don’t even want to be there and delight in intentionally turning the last 10 minutes (about 8% of a 2hr lecture) into an unlearnable environment. Ahhhhhhhh